Health

Children near lead smelters exposed to lead in the womb

The environmental tragedy in Flint, Michigan, in which drinking water contaminated with lead raised fears of potential health effects for exposed children, revealed the failure of a regulatory system to protect residents ...

Medical research

Dental enamel can't regenerate, right? Think again

Dental enamel is tricky stuff. Even though it's the body's hardest material, if it wears away from cavities, acidic food or drinks or overbrushing, it doesn't regenerate.

Dentistry

Orthodontics no guarantee of long-term oral health

A commonly held belief among the general public is orthodontic treatment will prevent future tooth decay. Research undertaken at the University of Adelaide has found that this is not the case.

Dentistry

Better oral health with new type of glass ceramic

Researchers at Ångström Laboratory at Uppsala University have now developed glass ceramics that are three times stronger than current ones. This paves the way for better dental care where patients benefit from stronger ...

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Tooth

Teeth (singular tooth) are small whitish structures found in the jaws (or mouths) of many vertebrates that are used to tear, scrape, and chew food. Some animals, particularly carnivores, also use teeth for hunting or defense. The roots of teeth are covered by gums. Teeth are not made of bone, but rather of tissues of varying density and hardness.

Teeth are among the most distinctive (and long-lasting) features of mammal species. Paleontologists use teeth to identify fossil species and determine their relationships. The shape of the animal's teeth are related to its diet. For example, plant matter is hard to digest, so herbivores have many molars for chewing. Carnivores, on the other hand, need canines to kill prey and to tear meat.

Mammals are diphyodont, meaning that they develop two sets of teeth. In humans, the first set (the "baby," "milk," "primary" or "deciduous" set) normally starts to appear at about six months of age, although some babies are born with one or more visible teeth, known as neonatal teeth. Normal tooth eruption at about six months is known as teething and can be painful.

Some animals develop only one set of teeth (monophyodont) while others develop many sets (polyphyodont). Sharks, for example, grow a new set of teeth every two weeks to replace worn teeth. Rodent incisors grow and wear away continually through gnawing, maintaining relatively constant length. Many rodents such as voles (but not mice) and guinea pigs, as well as rabbits, have continuously growing molars in addition to incisors.

This text uses material from Wikipedia, licensed under CC BY-SA